[cfe-commits] [PATCH] Support for pragma include_alias
Argyrios Kyrtzidis
kyrtzidis at apple.com
Fri Mar 2 14:48:35 PST 2012
On Mar 2, 2012, at 1:33 PM, Aaron Ballman wrote:
> On Fri, Mar 2, 2012 at 12:54 PM, Argyrios Kyrtzidis <kyrtzidis at apple.com> wrote:
>> On Mar 2, 2012, at 9:51 AM, Aaron Ballman wrote:
>>
>>> On Thu, Mar 1, 2012 at 8:07 PM, Argyrios Kyrtzidis <kyrtzidis at apple.com> wrote:
>>>> On Mar 1, 2012, at 10:43 AM, Aaron Ballman wrote:
>>>>
>>>>> On Thu, Mar 1, 2012 at 12:21 AM, Richard Smith <richard at metafoo.co.uk> wrote:
>>>>>> Hi,
>>>>>>
>>>>>>>> On Sun, Feb 19, 2012 at 5:31 PM, Aaron Ballman <aaron at aaronballman.com>
>>>>>>>> wrote:
>>>>>>>>> One of the MSVC pragmas is the ability to remap include filenames, as
>>>>>>>>> described in MSDN:
>>>>>>>>> http://msdn.microsoft.com/en-us/library/wbeh5h91.aspx
>>>>>>>>>
>>>>>>>>> The long and short of it is: you can use this pragma to map the source
>>>>>>>>> filename to a replacement filename (usually for supporting the old 8.3
>>>>>>>>> filenames on FAT systems, but can be used arbitrarily). For instance:
>>>>>>>>>
>>>>>>>>> #pragma include_alias( "FoobarIsReallyLong.h", "FOOBAR~1.H" )
>>>>>>>>> #include "FoobarIsReallyLong.h" // Actually opens up FOOBAR~1.H
>>>>>>>>>
>>>>>>>>> #pragma include_alias( <foo.h>, <bar.h> )
>>>>>>>>> #include <foo.h> // Actually includes <bar.h>
>>>>>>>>> #include "foo.h" // Still includes "foo.h"
>>>>>>>>>
>>>>>>>>> This patch implements that pragma, and closes Bug 10705.
>>>>>>
>>>>>>
>>>>>> Sorry for the delay!
>>>>>>
>>>>>>> Index: include/clang/Basic/DiagnosticLexKinds.td
>>>>>>> ===================================================================
>>>>>>> --- include/clang/Basic/DiagnosticLexKinds.td (revision 150897)
>>>>>>> +++ include/clang/Basic/DiagnosticLexKinds.td (working copy)
>>>>>>> @@ -292,6 +292,15 @@
>>>>>>> ExtWarn<"__has_warning expected option name (e.g. \"-Wundef\")">,
>>>>>>> InGroup<MalformedWarningCheck>;
>>>>>>>
>>>>>>> +def warn_pragma_include_alias_mismatch :
>>>>>>> + ExtWarn<"pragma include_alias requires matching include directives "
>>>>>>> + "(e.g include_alias(\"foo.h\", \"bar.h\") or "
>>>>>>> + "include_alias(<foo.h>, <bar.h>))">,
>>>>>>> + InGroup<UnknownPragmas>;
>>>>>>
>>>>>> Can we make this diagnostic clearer? I'd prefer for us to produce different
>>>>>> text depending on whether the source include was a "include" or a <include>.
>>>>>> As a first pass:
>>>>>>
>>>>>> angle-bracketed include <%0> cannot be aliased to double-quoted include "%1"
>>>>>> double-quoted include "%0" cannot be aliased to angle-bracketed include <%1>
>>>>>>
>>>>>>> +def warn_pragma_include_alias_expected :
>>>>>>> + ExtWarn<"pragma include_alias expected '%0'">,
>>>>>>> + InGroup<UnknownPragmas>;
>>>>>>> +
>>>>>>> def err__Pragma_malformed : Error<
>>>>>>> "_Pragma takes a parenthesized string literal">;
>>>>>>> def err_pragma_comment_malformed : Error<
>>>>>>> Index: include/clang/Lex/HeaderSearch.h
>>>>>>> ===================================================================
>>>>>>> --- include/clang/Lex/HeaderSearch.h (revision 150897)
>>>>>>> +++ include/clang/Lex/HeaderSearch.h (working copy)
>>>>>>> @@ -154,6 +154,9 @@
>>>>>>> llvm::StringMap<const DirectoryEntry *, llvm::BumpPtrAllocator>
>>>>>>> FrameworkMap;
>>>>>>>
>>>>>>> + llvm::StringMap<std::pair<StringRef, bool>, llvm::BumpPtrAllocator>
>>>>>>> + IncludeAliasMap;
>>>>>>
>>>>>> This map doesn't appear to be sufficient: the Microsoft documentation
>>>>>> indicates that "foo" and <foo> can be aliased to different includes.
>>>>>>
>>>>>> Also, the StringRef in the value type here will refer to a string whose
>>>>>> lifetime has ended.
>>>>>>
>>>>>>> +
>>>>>>> /// HeaderMaps - This is a mapping from FileEntry -> HeaderMap,
>>>>>>> uniquing
>>>>>>> /// headermaps. This vector owns the headermap.
>>>>>>> std::vector<std::pair<const FileEntry*, const HeaderMap*> > HeaderMaps;
>>>>>>> @@ -217,6 +220,25 @@
>>>>>>> SystemDirIdx++;
>>>>>>> }
>>>>>>>
>>>>>>> + /// AddHeaderMapping -- Map the source include name to the dest include
>>>>>>> name
>>>>>>> + void AddHeaderMapping(const StringRef& Source, const StringRef& Dest,
>>>>>>
>>>>>> Generally, please write " &" not "& ". Also, StringRefs are usually passed
>>>>>> by value.
>>>>>>
>>>>>>> + bool IsAngled) {
>>>>>>> + IncludeAliasMap[Source] = std::make_pair(Dest, IsAngled);
>>>>>>> + }
>>>>>>> +
>>>>>>> + StringRef MapHeader(const StringRef& Source, bool isAngled) {
>>>>>>> + // Do any filename replacements before anything else
>>>>>>> + llvm::StringMap<std::pair<StringRef,bool>>::const_iterator iter =
>>>>>>
>>>>>> Please capitalize IsAngled and Iter, and write "> >" not ">>". I don't like
>>>>>> repeating this type here (and especially not missing out the
>>>>>> llvm::BumpPtrAllocator argument); consider adding a typedef for your
>>>>>> container type.
>>>>>>
>>>>>>> + IncludeAliasMap.find(Source);
>>>>>>> + if (iter != IncludeAliasMap.end()) {
>>>>>>> + // If the angling matches, then we've found a replacement
>>>>>>> + if (iter->second.second == isAngled) {
>>>>>>> + return iter->second.first;
>>>>>>> + }
>>>>>>
>>>>>> Prevailing llvm/clang style is to omit the braces around a simple
>>>>>> single-statement body such as this.
>>>>>>
>>>>>>> + }
>>>>>>> + return Source;
>>>>>>> + }
>>>>>>> +
>>>>>>> /// \brief Set the path to the module cache.
>>>>>>> void setModuleCachePath(StringRef CachePath) {
>>>>>>> ModuleCachePath = CachePath;
>>>>>>> Index: include/clang/Lex/Preprocessor.h
>>>>>>> ===================================================================
>>>>>>> --- include/clang/Lex/Preprocessor.h (revision 150897)
>>>>>>> +++ include/clang/Lex/Preprocessor.h (working copy)
>>>>>>> @@ -1262,6 +1262,7 @@
>>>>>>> void HandlePragmaMessage(Token &MessageTok);
>>>>>>> void HandlePragmaPushMacro(Token &Tok);
>>>>>>> void HandlePragmaPopMacro(Token &Tok);
>>>>>>> + void HandlePragmaIncludeAlias(Token &Tok);
>>>>>>> IdentifierInfo *ParsePragmaPushOrPopMacro(Token &Tok);
>>>>>>>
>>>>>>> // Return true and store the first token only if any CommentHandler
>>>>>>> Index: lib/Lex/PPDirectives.cpp
>>>>>>> ===================================================================
>>>>>>> --- lib/Lex/PPDirectives.cpp (revision 150897)
>>>>>>> +++ lib/Lex/PPDirectives.cpp (working copy)
>>>>>>> @@ -1297,6 +1297,9 @@
>>>>>>> PragmaARCCFCodeAuditedLoc = SourceLocation();
>>>>>>> }
>>>>>>>
>>>>>>> + // Map the filename
>>>>>>> + Filename = HeaderInfo.MapHeader(Filename, isAngled);
>>>>>>> +
>>>>>>> // Search include directories.
>>>>>>> const DirectoryLookup *CurDir;
>>>>>>> SmallString<1024> SearchPath;
>>>>>>> Index: lib/Lex/Pragma.cpp
>>>>>>> ===================================================================
>>>>>>> --- lib/Lex/Pragma.cpp (revision 150897)
>>>>>>> +++ lib/Lex/Pragma.cpp (working copy)
>>>>>>> @@ -663,6 +663,101 @@
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> +void Preprocessor::HandlePragmaIncludeAlias(Token& Tok) {
>>>>>>> + // We will either get a quoted filename or a bracketed filename, and
>>>>>>> we
>>>>>>> + // have to track which we got. The first filename is the source name,
>>>>>>> + // and the second name is the mapped filename. If the first is quoted,
>>>>>>> + // the second must be as well (cannot mix and match quotes and
>>>>>>> brackets).
>>>>>>> + SourceLocation Loc = Tok.getLocation();
>>>>>>> +
>>>>>>> + // Get the open paren
>>>>>>> + Lex(Tok);
>>>>>>> + if (Tok.isNot(tok::l_paren)) {
>>>>>>> + Diag(Tok, diag::warn_pragma_include_alias_expected) << "(";
>>>>>>> + return;
>>>>>>> + }
>>>>>>> +
>>>>>>> + // We expect either a quoted string literal, or a bracketed name
>>>>>>> + Token SourceFilenameTok;
>>>>>>> + CurPPLexer->LexIncludeFilename(SourceFilenameTok);
>>>>>>> + if (SourceFilenameTok.is(tok::eod)) {
>>>>>>> + // The diagnostic has already been handled
>>>>>>> + return;
>>>>>>> + }
>>>>>>> +
>>>>>>> + StringRef SourceFileName;
>>>>>>> + SmallString<128> FileNameBuffer;
>>>>>>> + if (SourceFilenameTok.is(tok::string_literal) ||
>>>>>>> + SourceFilenameTok.is(tok::angle_string_literal)) {
>>>>>>> + SourceFileName = getSpelling(SourceFilenameTok, FileNameBuffer);
>>>>>>> + } else if (SourceFilenameTok.is(tok::less)) {
>>>>>>> + // This could be a path instead of just a name
>>>>>>> + FileNameBuffer.push_back('<');
>>>>>>> + SourceLocation End;
>>>>>>> + if (ConcatenateIncludeName(FileNameBuffer, End))
>>>>>>> + return; // Diagnostic already emitted
>>>>>>> + SourceFileName = FileNameBuffer.str();
>>>>>>> + } else {
>>>>>>> + Diag(Tok, diag::warn_pragma_include_alias_expected) << "include
>>>>>>> filename";
>>>>>>
>>>>>> English phrases shouldn't be used as diagnostic arguments, since they won't
>>>>>> be translatable (if we ever choose to translate the diagnostics). Please use
>>>>>> a different diagnostic for this; perhaps diag::err_pp_expects_filename?
>>>>>>
>>>>>> Also, I don't see a test for this error.
>>>>>>
>>>>>>> + return;
>>>>>>> + }
>>>>>>> + FileNameBuffer.clear();
>>>>>>> +
>>>>>>> + // Now we expect a comma, followed by another include name
>>>>>>> + Lex(Tok);
>>>>>>> + if (Tok.isNot(tok::comma)) {
>>>>>>> + Diag(Tok, diag::warn_pragma_include_alias_expected) << ",";
>>>>>>> + return;
>>>>>>> + }
>>>>>>> +
>>>>>>> + Token ReplaceFilenameTok;
>>>>>>> + CurPPLexer->LexIncludeFilename(ReplaceFilenameTok);
>>>>>>> + if (ReplaceFilenameTok.is(tok::eod)) {
>>>>>>> + // The diagnostic has already been handled
>>>>>>> + return;
>>>>>>> + }
>>>>>>> +
>>>>>>> + StringRef ReplaceFileName;
>>>>>>> + if (ReplaceFilenameTok.is(tok::string_literal) ||
>>>>>>> + ReplaceFilenameTok.is(tok::angle_string_literal)) {
>>>>>>> + ReplaceFileName = getSpelling(ReplaceFilenameTok, FileNameBuffer);
>>>>>>> + } else if (ReplaceFilenameTok.is(tok::less)) {
>>>>>>> + // This could be a path instead of just a name
>>>>>>> + FileNameBuffer.push_back('<');
>>>>>>> + SourceLocation End;
>>>>>>> + if (ConcatenateIncludeName(FileNameBuffer, End))
>>>>>>> + return; // Diagnostic already emitted
>>>>>>> + ReplaceFileName = FileNameBuffer.str();
>>>>>>> + } else {
>>>>>>> + Diag(Tok, diag::warn_pragma_include_alias_expected) << "include
>>>>>>> filename";
>>>>>>> + return;
>>>>>>> + }
>>>>>>
>>>>>> Could this repeated code be factored out? (I imagine we have largely the
>>>>>> same pattern in some other places too.)
>>>>>>
>>>>>>> +
>>>>>>> + // Finally, we expect the closing paren
>>>>>>> + Lex(Tok);
>>>>>>> + if (Tok.isNot(tok::r_paren)) {
>>>>>>> + Diag(Tok, diag::warn_pragma_include_alias_expected) << ")";
>>>>>>> + return;
>>>>>>> + }
>>>>>>> +
>>>>>>> + // Now that we have the source and target filenames, we need to make
>>>>>>> sure
>>>>>>> + // they're both of the same type (angled vs non-angled)
>>>>>>> + bool SourceIsAngled =
>>>>>>> + GetIncludeFilenameSpelling(SourceFilenameTok.getLocation(),
>>>>>>> + SourceFileName);
>>>>>>> + bool ReplaceIsAngled =
>>>>>>> + GetIncludeFilenameSpelling(ReplaceFilenameTok.getLocation(),
>>>>>>> + ReplaceFileName);
>>>>>>> + if (SourceIsAngled != ReplaceIsAngled) {
>>>>>>> + Diag(Loc, diag::warn_pragma_include_alias_mismatch);
>>>>>>> + return;
>>>>>>> + }
>>>>>>> +
>>>>>>> + // Now we can let the include handler know about this mapping
>>>>>>> + getHeaderSearchInfo().AddHeaderMapping(SourceFileName,
>>>>>>> ReplaceFileName,
>>>>>>
>>>>>> ReplaceFileName here refers to a string which expires at the end of this
>>>>>> function, and it's being saved away by AddHeaderMapping for later use.
>>>>>>
>>>>>>> + SourceIsAngled);
>>>>>>> +}
>>>>>>> +
>>>>>>> /// AddPragmaHandler - Add the specified pragma handler to the
>>>>>>> preprocessor.
>>>>>>> /// If 'Namespace' is non-null, then it is a token required to exist on
>>>>>>> the
>>>>>>> /// pragma line before the pragma string starts, e.g. "STDC" or "GCC".
>>>>>>> @@ -943,6 +1038,15 @@
>>>>>>> }
>>>>>>> };
>>>>>>>
>>>>>>> +/// PragmaIncludeAliasHandler - "#pragma include_alias("...")".
>>>>>>> +struct PragmaIncludeAliasHandler : public PragmaHandler {
>>>>>>> + PragmaIncludeAliasHandler() : PragmaHandler("include_alias") {}
>>>>>>> + virtual void HandlePragma(Preprocessor &PP, PragmaIntroducerKind
>>>>>>> Introducer,
>>>>>>> + Token &IncludeAliasTok) {
>>>>>>> + PP.HandlePragmaIncludeAlias(IncludeAliasTok);
>>>>>>> + }
>>>>>>> +};
>>>>>>> +
>>>>>>> /// PragmaMessageHandler - "#pragma message("...")".
>>>>>>> struct PragmaMessageHandler : public PragmaHandler {
>>>>>>> PragmaMessageHandler() : PragmaHandler("message") {}
>>>>>>> @@ -1095,5 +1199,6 @@
>>>>>>> // MS extensions.
>>>>>>> if (Features.MicrosoftExt) {
>>>>>>> AddPragmaHandler(new PragmaCommentHandler());
>>>>>>> + AddPragmaHandler(new PragmaIncludeAliasHandler());
>>>>>>> }
>>>>>>> }
>>>>>>> Index: test/Preprocessor/pragma_microsoft.c
>>>>>>> ===================================================================
>>>>>>> --- test/Preprocessor/pragma_microsoft.c (revision 150897)
>>>>>>> +++ test/Preprocessor/pragma_microsoft.c (working copy)
>>>>>>> @@ -38,3 +38,20 @@
>>>>>>> // this warning should go away.
>>>>>>> MACRO_WITH__PRAGMA // expected-warning {{expression result unused}}
>>>>>>> }
>>>>>>> +
>>>>>>> +
>>>>>>> +// This should include macro_arg_directive even though the include
>>>>>>> +// is looking for test.h This allows us to assign to "n"
>>>>>>> +#pragma include_alias("test.h", "macro_arg_directive.h" )
>>>>>>> +#include "test.h"
>>>>>>> +void test( void ) {
>>>>>>> + n = 12;
>>>>>>> +}
>>>>>>> +
>>>>>>> +#pragma include_alias("foo.h", <bar.h>) // expected-warning {{pragma
>>>>>>> include_alias requires matching include directives (e.g
>>>>>>> include_alias("foo.h", "bar.h") or include_alias(<foo.h>, <bar.h>))}}
>>>>>>> +#pragma include_alias("test.h") // expected-warning {{pragma
>>>>>>> include_alias expected ','}}
>>>>>>> +
>>>>>>> +// Make sure that the names match exactly for a replacement, including
>>>>>>> path information. If
>>>>>>> +// this were to fail, we would get a file not found error
>>>>>>> +#pragma include_alias(".\pp-record.h", "does_not_exist.h")
>>>>>>> +#include "pp-record.h"
>>>>>>
>>>>>
>>>>> Hi Richard -- I've addressed almost all of the points in your review,
>>>>> and have attached a patch for you to check over again. Thank you for
>>>>> all the helpful feedback!
>>>>>
>>>>> The only thing I didn't address was:
>>>>>
>>>>>> Could this repeated code be factored out? (I imagine we have largely the
>>>>>> same pattern in some other places too.)
>>>>>
>>>>> I'm guessing the code could be refactored out, but I'd rather that be
>>>>> a separate patch since it touches on more than just include_alias.
>>>>>
>>>>> Thanks!
>>>>
>>>> A few additional comments, I suggest optimizing for the common path, that there is no include_alias in the source, so:
>>>>
>>>> + typedef llvm::StringMap<std::string, llvm::BumpPtrAllocator>
>>>> + IncludeAliasMap;
>>>> + IncludeAliasMap IncludeAliases;
>>>>
>>>> Have this be a pointer and create the object lazily on demand:
>>>> OwningPtr<IncludeAliasMap> IncludeAliases;
>>>>
>>>> + // Map the filename with the brackets still attached. If the name doesn't
>>>> + // map to anything, fall back on the filename we've already gotten the
>>>> + // spelling for.
>>>> + std::string NewName = HeaderInfo.MapHeader(OriginalFilename);
>>>> + if (!NewName.empty())
>>>> + Filename = NewName;
>>>> +
>>>>
>>>> here you can check if the object was created or not before going ahead to call HeaderInfo.MapHeader(OriginalFilename).
>>>>
>>>> + void AddHeaderMapping(StringRef Source, StringRef Dest) {
>>>> and
>>>> + std::string MapHeader(StringRef Source) {
>>>>
>>>> Rename to "AddIncludeAlias" and "MapHeaderToIncludeAlias" to make clear what these are for ?
>>>
>>> Thanks for the reviews -- I've attached a patch with your suggestions
>>> incorporated. I've cleaned up the items Richard pointed out, and made
>>> the alias mapping lazy-loaded as Argyrios suggested.
>>
>> Thanks Aaron. Another thing I'd like to bring to your attention:
>>
>> Since all the include_alias related methods are only used by the preprocessor, how about moving the methods and IncludeAliases object to the Preprocessor and make them all private ?
>
> I've been thinking about this, and it doesn't sit quite right with me.
> Since this is so heavily related to header files, I think it's a bit
> cleaner to pack it in with the HeaderSearch functionality. Keeps all
> the logic in one place.
>
> Do you have strong feelings against that?
No, committing is fine by me.
>
> ~Aaron
>
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